[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Whatever happend to compression?




Robert Glenn writes:
> Actually, I have a paper here in front of me, "Contemporary
> Cryptology:  An Introduction" by James Massey that talks about
> compression and security.  The section that talks about this explains
> how redundancy in the data can be used to help break "an imperfect
> cipher".  Since compression removes redundance the article suggests
> "...that data compression is a useful cryptographic tool."  It goes on
> to imply that the practice of removing redundancy from data before
> encrypting has been going on for quite some time.

The problem is the way that many modern compression algorithms work,
they leave lots of nearly known plaintext in the data stream. I don't
know that this can be well exploited, but I suspect it can.

Perry


References: